These were all extract with steeped grains and other adjuncts recipes, not pure extract, and your readings aren't exactly in line to show an obvious fault with the hydrometer. The difference between 60 and 70 F is about .001 gravity units. I would keep searching for an answer. Or just buy another hydrometer and use both to see if there's a sliding scale difference.

Actually, 10 degrees will put you off by about .003, still not enough to explain your numbers though.

If it is the hydrometer, then it doesn't really matter... The thing that matters is the difference from OG to the FG. the OG doesn't matter until you are trying to find your efficiency, or until you're worried about how many yeast cells you need to pitch (even then you can only go by the predicted OG since after the wort is made you won't have time to make a starter with the correct number of cells)

My guess is still probably a combination of volume, not steeping long enough in the correct temp, and hydrometer. Start by finding the final volume. Then you can either use a calc our you can just do:

If your target is 1.130 at 5 gallons but you have just over 6, you'll be around 1.106. Likewise, if your target is 1.074 for 5 gallons but you have just under 6 gallons, you'll be around 1.064.

This is most likely your problem. You need to mark whatever you are fermenting in with accurate levels do you know how much volume of wort you have after your boil. We need to know how much wort you have post boil to be able to help anymore.

If your target is 1.130 at 5 gallons but you have just over 6, you'll be around 1.106. Likewise, if your target is 1.074 for 5 gallons but you have just under 6 gallons, you'll be around 1.064.

+1. A few recommendations:
1. Adjust your water volume from the start based on your usual boil-off volume to hit your desired post-boil volume.
2. Mark a spoon or measuring stick with various volumes in your brew pot so you can monitor volume during boil and adjust boil intensity depending on boil-off rate
3. Intentionally undershoot volume and use top-off water to hit target volume. This can even be added progressively in the last 5-10 minutes of boil to ensure it mixes in properly and is boiled with your full volume (as long as it doesn't kill your boil).